Process of preparing artificial fibers



Patented Oct. 6, 1942 ,4

UNITED s'rATss PATENT OFFICE;

PBoOCESS F PgggggNG 4 'Oskar Huppert, Chicago, 111., assignor to TheGlidden Company, Cleveland, Ohio, at corporation of Ohio No Drawing.Original application May 13, 1940,

Serial N 334,920. Divided and this application March 10, 1941, SerialNo. 382,577

3Claims.

The present invention relates to the production of artificial fibersfrom soya protein, such as artificial wool and the like.

The present application is a division of application Serial No. 334,920,filed May 13, 1940.

In the manufacture of artificial protein fibers, a spinning solution ofthe protein is extruded through spinnerets into a coagulating bath andthe fibers are then hardened. After hardening the fibers are'washed,subjected to an aftertreatment, and may be variously treated to producethe finished fiber.

In the case of casein, for example, the fibers, after hardening, do notstick together and may be subjected to washing and the after-treatmentwithout any particular difiiculty. In the case of soya protein fibers,however, the individual fibers or filaments after hardening are stickyand ad- .herent with the result that they stick together to form acoherent mass, thereby preventing successful after-treatment, cardingand the like.

It is,- therefore, an object of the present invention to overcome theaforementioned-sticking of the hardened soya protein fiber.

It is a further object of the present invention to treat the hardenedfilms before washing or other treatments to overcome the aforementionedsticking. a

The invention is applicable to any fiber prepared from soya protein. Thefiber may be spun from suitable solutions of either hydrolyzed orunhydrolyzed protein. Th spinning solution may also comprise in whole orin part a soya protein disulfide'prepared in accordance with UnitedStates Patent No. 2,112,210. Such a protein disulfideis prepared bytreating a soya protein hydrolysate with carbon disulfide at a hydroxylion concentration which corresponds at most to that ofa solution ofcalcium hydroxide and then oxidizing the thus sulfurized protein to formthe disulfi de. The objects of the present invention may be accomplishedby subjecting the hardened fiber,

before washing, to the action of nitrous acid. The

action of the nitrous acid is such that the fibers 'lose theirstickiness and may thereafter be washed, subjected to an aftertreatment,and otherwis successfully handled. It is surprising that the strength,elasticity, and flexibility of the fibers are not diminished by thetreatment with nitrous acid. on the contrary, they become more resistantto boiling water and take dyes more easily. By this treatment the fibersbecome hydrophobic permanently waterproof and fast to washing and drycleaning.

The treatment with nitrous acid maybe effected in any suitable way. Thefibers maybe immersed in a'solution of nitrous acid for a short time.Preferably when the fibers are acid, such 5 as when-they are coagulatedin an acid bath, they may be immersed in a solution of sodium nitrite orother suitable nitrous acid forming substance.

The following examples are illustrative.

Example I grams of sodium hydroxide. This solution is allowed to ripenone or two days and the spinning solution soobtained, after being freedof air, is

spun into a coagulating bath of a combination of 25% sulfuric acid and15% sodium sulfate. The

fibers are then treated in a hardening bath containing 5% formaldehydeand 8% sodium chlo- 20 ride. The acid containing fibers, before washingare then treated for 5 minutes in a 2% solution.

- of sodium nitrite, after which they are washed.

, No sticking. difiiculty is encountered during the washing operationand the fibers may be sub- .iected to an after-treatment and otheroperations without encountering sticking difiiculties.

' Example II then bubbled into the solution at 60? C. with vigorousstirringfor an hour. The solution is allowed to cool to room temperaturewhile agitat- 40 ing. The spinning of 'the. fibers, coagulation,

hardening and nitrous acid treatment is thereafter the same as inExample I.

It will be understood that the detailed procedures described are capableof variation and modification without departing from the spirit andscope of the invention defined in the appended claims. I claim:

'1. The processor preparing artificial fibers 59 comprising spinninginto a coagulating bath to form fibers a solution containing soyaprotein disulfide prepared by treating soya protein hydrolysate withcarbon disuliide at a hydroxyl ion con-. centration which atmostcorresponds to that of a solution of calcium hydroxide and oxidizingthe 300 grams of hydrolyzed soya protein are dissolved in 1560 cc. ofwater with the acid of 15 thus suliurized protein to produce thedisulfide,

resulting sulfurized protein to form the disulflde.

3. The process which comprises treating with nitrous acid a disulfideprotein fiber spun from a solution of a protein disulfid resulting .Iromtreatment of protein with carbon disuiflde and oxidation of theresulting sulfurized protein to form the disulfide.

' OSKAR HUPPERT.

